Persistent Email Storage With Multiple Backend Options

** - MailSandbox (a fork of Mailpit) is a fast, zero-dependency email testing tool & API with a web UI, SMTP server, Postmark API emulation, and MCP server for AI-assisted debugging.

Unique: Pluggable storage backend architecture allows switching between in-memory, SQLite, and PostgreSQL without code changes — enables development with in-memory storage and production-like testing with persistent databases

vs others: More flexible storage options than Mailpit (which uses SQLite only) because MailSandbox supports multiple backends, allowing teams to choose persistence strategy matching their infrastructure